Roll over, Dr. Dre, and tell Gwen Stefani the news  Eve has recorded a rap for a song by the Chemical Brothers.

The track, "Hot Acid Rhythm," won't be on the group's next album, Come With Us, scheduled for release January 29. It will likely surface in Europe as the B-side to a future single.

If news of this collaboration seems surprising, it was a bit of a shocker for the electronic music duo as well.

"To be honest, we don't really understand how it happened," Brother Ed Simons said Tuesday at New York's Royalton Hotel. "We didn't call her. Someone did, though. In the past, we've been closely involved with all the collaborations we've done. People have always come to the studio and we've worked together. This is the first time we've done anything through the mail."

Simons' musicmate, Tom Rowlands, described the track as "a strange sort of Jamaican acid explosion," but Simons quickly added that the song's not quite finished.

"She's done her bit," Simons said. "But we've still got to mix it and make it flow a bit better."

The duo said the song will likely come out in America in some form (an Eve-free "Hot Acid Rhythm 1" is on the U.S. version of the Brothers' single "It Began in Afrika," released last month), and they hope that the pairing will pave the way for future hip-hop projects.

"It's something we've always tried to do," Simons said. "When we were working on Come With Us, we sent a couple of the tracks to Outkast to see if they wanted to do something with us. They said they were quite into the music we sent them, but then they blew up and became more massive. But maybe that's something for the future."

"It Began in Afrika" is #3 on the Billboard Hot Dance Music/Club Play chart this week after spending last week at #1. With its tumbling tribal beats, jungle sound effects and pulsing percussive loops, the tune is one of the highlights of Come With Us, an eclectic, otherworldly dance disc that further expands the Chemical Brothers' sonic parameters.

"It's a song that we knew would sound exciting on the dance floor," Simons said. "A lot of what the track is about is the drums and how exciting the drums are to listen to. It's a good combination of four-to-the-floor banging bass drum and this wall of percussion that sounds pretty much live. I like the idea of having drums that sound quite live and then really sequenced drums along with all the sound effects. When you play it on the dance floor, all the lion noises and the bird 'caw-caw-caws' create a big, heady brew."